The MMC won't close

On Exchange 2000 SP2 on Windows 2000 SP2, the mmc.exe won't close when I close admin Windows. Sometimes I'll have 8-10 open in Task Manager at the end of the day. Any ideas what's going on here?
MMC.exe is the parent process for the Microsoft Management Console. Within the MMC you can add one or more snap-ins. So, when you say MMC won't close, it doesn't help because I don't know what snap-ins or snap-in extensions you are running. Also, I don't know if you are saving the console file (.msc file) or not, as well.

See if you can isolate which snap-in(s) is/are causing the problem, and then submit a follow-up question with that info.